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|
/*
* lis3lv02d.c - ST LIS3LV02DL accelerometer driver
*
* Copyright (C) 2007-2008 Yan Burman
* Copyright (C) 2008 Eric Piel
* Copyright (C) 2008-2009 Pavel Machek
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/dmi.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <linux/input-polldev.h>
#include <linux/delay.h>
#include <linux/wait.h>
#include <linux/poll.h>
#include <linux/freezer.h>
#include <linux/uaccess.h>
#include <linux/miscdevice.h>
#include <asm/atomic.h>
#include "lis3lv02d.h"
#define DRIVER_NAME "lis3lv02d"
/* joystick device poll interval in milliseconds */
#define MDPS_POLL_INTERVAL 50
/*
* The sensor can also generate interrupts (DRDY) but it's pretty pointless
* because they are generated even if the data do not change. So it's better
* to keep the interrupt for the free-fall event. The values are updated at
* 40Hz (at the lowest frequency), but as it can be pretty time consuming on
* some low processor, we poll the sensor only at 20Hz... enough for the
* joystick.
*/
#define LIS3_PWRON_DELAY_WAI_12B (5000)
#define LIS3_PWRON_DELAY_WAI_8B (3000)
/*
* LIS3LV02D spec says 1024 LSBs corresponds 1 G -> 1LSB is 1000/1024 mG
* LIS302D spec says: 18 mG / digit
* LIS3_ACCURACY is used to increase accuracy of the intermediate
* calculation results.
*/
#define LIS3_ACCURACY 1024
/* Sensitivity values for -2G +2G scale */
#define LIS3_SENSITIVITY_12B ((LIS3_ACCURACY * 1000) / 1024)
#define LIS3_SENSITIVITY_8B (18 * LIS3_ACCURACY)
#define LIS3_DEFAULT_FUZZ 3
#define LIS3_DEFAULT_FLAT 3
struct lis3lv02d lis3_dev = {
.misc_wait = __WAIT_QUEUE_HEAD_INITIALIZER(lis3_dev.misc_wait),
};
EXPORT_SYMBOL_GPL(lis3_dev);
static s16 lis3lv02d_read_8(struct lis3lv02d *lis3, int reg)
{
s8 lo;
if (lis3->read(lis3, reg, &lo) < 0)
return 0;
return lo;
}
static s16 lis3lv02d_read_12(struct lis3lv02d *lis3, int reg)
{
u8 lo, hi;
lis3->read(lis3, reg - 1, &lo);
lis3->read(lis3, reg, &hi);
/* In "12 bit right justified" mode, bit 6, bit 7, bit 8 = bit 5 */
return (s16)((hi << 8) | lo);
}
/**
* lis3lv02d_get_axis - For the given axis, give the value converted
* @axis: 1,2,3 - can also be negative
* @hw_values: raw values returned by the hardware
*
* Returns the converted value.
*/
static inline int lis3lv02d_get_axis(s8 axis, int hw_values[3])
{
if (axis > 0)
return hw_values[axis - 1];
else
return -hw_values[-axis - 1];
}
/**
* lis3lv02d_get_xyz - Get X, Y and Z axis values from the accelerometer
* @lis3: pointer to the device struct
* @x: where to store the X axis value
* @y: where to store the Y axis value
* @z: where to store the Z axis value
*
* Note that 40Hz input device can eat up about 10% CPU at 800MHZ
*/
static void lis3lv02d_get_xyz(struct lis3lv02d *lis3, int *x, int *y, int *z)
{
int position[3];
int i;
mutex_lock(&lis3->mutex);
position[0] = lis3->read_data(lis3, OUTX);
position[1] = lis3->read_data(lis3, OUTY);
position[2] = lis3->read_data(lis3, OUTZ);
mutex_unlock(&lis3->mutex);
for (i = 0; i < 3; i++)
position[i] = (position[i] * lis3->scale) / LIS3_ACCURACY;
*x = lis3lv02d_get_axis(lis3->ac.x, position);
*y = lis3lv02d_get_axis(lis3->ac.y, position);
*z = lis3lv02d_get_axis(lis3->ac.z, position);
}
/* conversion btw sampling rate and the register values */
static int lis3_12_rates[4] = {40, 160, 640, 2560};
static int lis3_8_rates[2] = {100, 400};
/* ODR is Output Data Rate */
static int lis3lv02d_get_odr(void)
{
u8 ctrl;
int shift;
lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
ctrl &= lis3_dev.odr_mask;
shift = ffs(lis3_dev.odr_mask) - 1;
return lis3_dev.odrs[(ctrl >> shift)];
}
static int lis3lv02d_set_odr(int rate)
{
u8 ctrl;
int i, len, shift;
lis3_dev.read(&lis3_dev, CTRL_REG1, &ctrl);
ctrl &= ~lis3_dev.odr_mask;
len = 1 << hweight_long(lis3_dev.odr_mask); /* # of possible values */
shift = ffs(lis3_dev.odr_mask) - 1;
for (i = 0; i < len; i++)
if (lis3_dev.odrs[i] == rate) {
lis3_dev.write(&lis3_dev, CTRL_REG1,
ctrl | (i << shift));
return 0;
}
return -EINVAL;
}
static int lis3lv02d_selftest(struct lis3lv02d *lis3, s16 results[3])
{
u8 reg;
s16 x, y, z;
u8 selftest;
int ret;
mutex_lock(&lis3->mutex);
if (lis3_dev.whoami == WAI_12B)
selftest = CTRL1_ST;
else
selftest = CTRL1_STP;
lis3->read(lis3, CTRL_REG1, ®);
lis3->write(lis3, CTRL_REG1, (reg | selftest));
msleep(lis3->pwron_delay / lis3lv02d_get_odr());
/* Read directly to avoid axis remap */
x = lis3->read_data(lis3, OUTX);
y = lis3->read_data(lis3, OUTY);
z = lis3->read_data(lis3, OUTZ);
/* back to normal settings */
lis3->write(lis3, CTRL_REG1, reg);
msleep(lis3->pwron_delay / lis3lv02d_get_odr());
results[0] = x - lis3->read_data(lis3, OUTX);
results[1] = y - lis3->read_data(lis3, OUTY);
results[2] = z - lis3->read_data(lis3, OUTZ);
ret = 0;
if (lis3->pdata) {
int i;
for (i = 0; i < 3; i++) {
/* Check against selftest acceptance limits */
if ((results[i] < lis3->pdata->st_min_limits[i]) ||
(results[i] > lis3->pdata->st_max_limits[i])) {
ret = -EIO;
goto fail;
}
}
}
/* test passed */
fail:
mutex_unlock(&lis3->mutex);
return ret;
}
void lis3lv02d_poweroff(struct lis3lv02d *lis3)
{
/* disable X,Y,Z axis and power down */
lis3->write(lis3, CTRL_REG1, 0x00);
}
EXPORT_SYMBOL_GPL(lis3lv02d_poweroff);
void lis3lv02d_poweron(struct lis3lv02d *lis3)
{
u8 reg;
lis3->init(lis3);
/* LIS3 power on delay is quite long */
msleep(lis3->pwron_delay / lis3lv02d_get_odr());
/*
* Common configuration
* BDU: (12 bits sensors only) LSB and MSB values are not updated until
* both have been read. So the value read will always be correct.
*/
|